A patching formulation can be used for patching of plywood or concrete flooring, walls, ceilings, block materials and concrete plank. Cementitious patching materials are used for a broad spectrum of applications. The state of the art technology in this type of patches is Calcium Alumina Cement (CAC), sometimes referred to as High Alumina Cement formulations (HAC).
Formulations described in U.S. Pat. No. 6,833,186 provide an abrasion resistant coating composition comprising alumina and silica. DE 2129058 discloses mortar mixtures based on cement, sand additives for plastering floors. U.S. Pat. No. 4,735,027 provides coating formulations with silica sand, cement and a particulate, non-fibrous filler.
Various parameters must be considered in choosing a patch formulation. Preferably, a patch formulation should adhere well to a surface over which it is applied. It is also important that after the patch sets, it should be easy to sand the patch surface and prepare it for receiving a coat of paint.
Many patch formulations currently available on the market harden by evaporating water. This may lead to cracking, loose fit and eventual dislodging of the patch from surface to which it is adhered.
There is a need for patching materials which are easier to trowel, have higher extensions in addition to being high-strength and self-drying. There is also a need for improvement of re-workability of patch products and longer pot life; so that patching materials can be applied with less waste and larger volumes can be made for deeper applications and/or larger areas.